The penis is not usually the first thing I look for or notice about a dog.... Maybe there's more you're not telling us?

No. 72, obviously most people do not go about life checking dogs to see if they have a penis or not. You're an ass. It is a basic way to identify dogs, since they are not capable of speaking and telling us that they are Fido or Rover. The groomers should have noticed that the genitalia of the dog was female and the customer was supposed to be picking up a male. I do not own a dog dog but my best friend does and she informs me that at her groomers one of the first things they do is check the dog's genitals to be sure they don't make this kind of error. Obviously they don't want to make a mistake. Some dogs are mutts with no monetary value but some are very expensive, valuable purebreds. They don't want to accidentally hand over a $5,000 purebred to the owner of a mongrel and have that person take off with someone else's expensive dog. A look at the gender is the first of several checks they make to ensure the right dog goes back to the right owner. This does not make them sick freaks.

Read the OP's first sentence and note the phrase "small female terrier." Note the second sentence, which is, "My dog is a full grown male maltese." The OP clearly states that the dog on the OP's couch was female but the dog the OP actually owned was male. Unless you are just making a snide, childish remark about checking the dog's gender, you have extremely poor reading comprehension skills.